Synthetic resin compositions



Patented Sept. 3, 1940 UNITED STATES] PATENT OFFICE 7 2,213,201 SYNTHETIC RESIN ooMrosrrIoNs Edgar O. Britton and Gerald H. Coleman, Midland, Micln, assignors toThe Dow Chemical Company, Midland, Mich., a corporation of Michigan No Drawing.

Application August 17, 1938', Serial No. 225,262

X 16 Claims. (01. 260-36) This invention concerns new synthetic resin "compositions comprising resins derived from styrene and, as plasticizlng agents therefor, certain halogenated diphenyl aliphatic hydrocarbons.

It is known that solid resinous-products may be obtained by polymerizing monomeric styrene together with a variety of other unsaturated or ganic compounds containing olefinic linkages.

m For example, Staudinger (U. S. Patent 2,089,444)

discloses resinous polymers prepared by the conjoint polymerization of styrene and divinyl benzene. Voss .et a1. (U. S. Patent 2,047,398) describe similar p olymers prepared from styrene 15. and maleic acid derivatives, and in the co-pending applications of Britton et al., Serial No. 191,958, filed February 23, 1938; Serial No. 191,959, filed February 23, 1938; Serial No. 191,960, ffiled February 23, 1938; Serial No.

20 199,892, filed April 4, 1938; Serial No. 213,022,

filed June 10, 1938; and Serial No.- 217,224, filed July 2, 1938 are described products prepared by polymerizing styrene in the presence of certain unsaturated esters and ethers, 'e. g. triallyl phos- 25 phate,'ally1 crotonate, the dicinnamate of 14- pable only of swelling to form insoluble gels when contactedwith such solvents. Theopaque,v

white, friable polymers are insoluble and non- 4 swelling in polystyrenefsolvents; ,All such solid polymers, althoughtheir exact chemical-structure is not definitely known. Similarly the unsaturated compounds which maybe employed in polymerizing agents, andthepolymerization of mixturesofstyrene and suchagentsis referred to as co-polymerization. 'All of the, co-poly-j mers of-styrene possess, a number of, properties 55 which render them valuable in the manufacture resinous products are herein-referred to as,

. o preparingsuch products are referred to as coof molded or shaped objects, e. g. stability against discoloration, good dielectric strength, high mechanical strength, impermeability to moisture, resistance to attack by acids and alkalies, etc;

In preparing such molded or shaped objects, 5 3

however, it is advantageous to incorporate plasticizing or softening agents with the c'o-polymers for the purpose of increasing flow during molding or for increasing the flexibility, toughness, or resistance to shock, etc. of the finished article. We are aware that a number of materials, e. g. diphenyl methane, diphenyl propane, dixylyl ethane, chlorinated diphenyl, etc., have been suggested as plasticizing agents for polystyrene itself, but most of such agents are unsatisfactory for use with the co-polymers of styrene since they impart the desired properties to the copolymers only when used in suchlarge proportions as to reduce greatly the tensile strength and heat resistanceof the composition. Certain of such known plasticizing agents are further -dis'- advantageous in that they tend ,to vaporize or exudeto the surface of the plasticized compositon with resultant loss in plasticizing action and, frequently, blushing of the finishedproduct.

, We' have now found that certain halogenated diphenyl aliphatic hydrocarbons may be adv'an tageously employed as plasticizing agents for v the c'o-polymersof styrene in preparing com- 80 positions useful in the manufactureof molded or shaped objects. Styrene co-polymers. plasticized with these new agents are tougher and more resistant to shock than the unplasticized co-polymers, but at the same time they retaintheir initial high strength characteristics and heatresistance to' a much greater degree than do styrene co-polymers plasticized with known plasticizing agents. In some cases, the plasticized co-polymers even. show increased tensile strengths because of the improved molding-secured through the use of the new. plasticizing agents. Moreover, the plasticized-compositions are clear and transparent and show less. tendency u to blush or craze upon. aging than'do the unplasticized co-polymers.

The halogenated diaryl aliphatic hyrocarbons which are employed as plasticizing agents for the co-polymers. of- "styrene are di-(halophenyl). 5o

alkanes hayingthe general formula:

wherein R represents an alkylene radical, X represents chlorine or bromine, and n represents an integer not greater than 5, preferably not greater than 3. Examples of such compounds are (ii-("- chlorphenyl-) methane, di -(2.4-dibromphenyl-) butane, di-(2.4.6-tribromophenyl-) octane, di- (2-bromphenyl-) decane, di-(-chlorphenyl) ethane, di-(3-bromphenyl-) isobutane, til-(3.5- dichlorphenyl-) isopentane, di-(pentachlo'rphenyl-) methane, etc. These compounds vary in physical characteristics from colorless highboiling liquids to crystalline solids. They are compatible with styrene co-polyrners and may be employed to plasticize the same without excessively reducing tensile strength and heat resistance.

The new plastic compositions comprising styrene co-polymers plastioized with di (halophenyl-) alkanes are conveniently prepared by polymerizing a mixture of monomeric styrene, a co-polymerizing agent, and the plasticizing agent. The latter may be employed in any proportion within the limits of its compatability with the copolymer, but is usually employed in an amount representing from 5 to 40 per cent of the entire composition. The most efiective amount of plasticizing agent depends somewhat upon the use to which the composition is to be put. The co-polymerizing agents are usually employed in proportions representing from 0.1 to 25 per cent by weight of the styrene, although the optimum amount depends upon the particular co-polymerizing agent employed and upon the properties desired in the composition. The polymerization is usually carried out by heating the mixture of monomeric styrene, plasticizing agent, and copolymerizing agent at a moderately elevated temperature, e. g. 60 to 180 C. for 3-14 days, during which time the mixture gradually polymerizes to form a clear, transparent, thermoplastic resin having the plasticizing agent homogeneously dispersed throughout. A large amount of heat is developed during polymerization and when operating on a large scale it is advantageous'to provide heat dissipating means in order to maintain the desired temperature. If desired, the polymerization may be initiated at a relatively low merizing a mixture of monomeric styrene and a co-polymerizing agent, and thereafter causing the co-polymer to swell to a gel in a solution of the plasticizing agent in a solvent which is capable of swelling the co-polymer, e. g. benzene, toluene, carbon tetrachloride, etc. During the swelling operation, the plasticizing agent-is absorbed by the co-polymer gel, and, after removal of the solvent, the co-polymer is recovered in the form of a granular or fibrous mass containing the plasticizing agent in uniform and intimate dispersion therethrough. This method of incorporating a plasticizing agent with a styrene copolymer forms the subject matter of the co-pend ing application of Britten and Marshall, Serial No. 209,736, filed May 24., 1938.

A third method which may be employed in preparing the new compositions comprises mechanically mixing the finely divided co-polymer with the plasticizing agent in a Banbury or other suitable mixer until a homogeneous composition is obtained.

The following examples illustrate a number of ways in which the principle of the invention has been applied, but are not to be construed as limiting the same.

Example 1 Compositions comprising the co-polymer of styrene and the di-cinnamate of 1.4-dioxanediol- 2.3 plasticized with various di-(chlorphenyl-) alkanes were prepared by polymerizing mixtures containing 50.0 parts of monomeric styrene, 0.25 part of the di-cinnamate of lA-dioxanediol-ZB, and 5.0 parts of the plasticizing agent. The polymerization was carried out by heating the mixtures at 100 C. for 7 or 14 days. All of the compositions so prepared were clear transparent resins which were insoluble in alcohol but capable of being swelled to insoluble gels by benzene. These products were ground, dried, and molded into test specimens which were tested for mechanical strength, hardness, and heat resistance. The data obtained, together with comparative data on the unplastlcized co-polymer as well as data on the co-polymer plasticized with the known plasticizing agent, dlphenyl propane, are present in Table 1 below:

Table 1 (Jo-polymerizing agent Plasticizlng agent Polymerization at m W an. at No Per Per Time Temp temp" in l b s ll i x i ri (s l i zi r e) point T Lame cent Name cent hours 0. q

Di-clnnamatepf 0.5 108 100 100 0.9 6,900 77 110 -dioxanedwl- 2 10o 0.5 1.2 dl-phonylpropane 0.0v 168 150 0.9 5.750 75 48 100 .410 0.5 lilll'fl-chlorphenyt) 0.0 108 100 160 2.1 8,800 80 6 104 4 do 0.5 l.2-di-(4-chlorphonyl-) 0.0 168 100 -100 1.1 7,200 71 58 110 propane.

6 io 0.5 l.%-dti)-(-chlorpbonyl-) 0.0 336 100 100 1.0 8,400 83 6 111 6 do 0.5 l.2-di-(2.5-dlchlorphen- 0.0 168 100 100 1.0 9,600 74 76 116 yl-) ropane.

7 d0 0.5 1.2-di-( A-dichlorphenyt) 0.0 168 100 150 0.8 7,000 76 69 propane.

0.5 1.2-tri-(2.4.6-trlch1or- 9.0 330 100 100 0.8 8,300 so 68 90 phenyl-) ethane.

Example 2 temperature, e. g. 60 C., and the temperature gradually increased as polymerization proceeds.

Compositions comprising styrene co-polymers which are capable of being swelled by solvents may be prepared by forming the co-polymer in the absence of the plastlcizing agent, i. e. by poly- A number of compositions were prepared by polymerizing mixtures of monomeric tyrene and various co-polymerizing agents in the presence of 1.2-di-(4-chlorphenyl-) ethane as in Example 1. The plasticized compositions were ground,

dried, and molded into test specimens. The test porated therein. A molded test specimen was data obtained are tabulated below:

considerably less brittle and molded more. readily Table 2 (Jo-polymerizing agent Plasticizing agent Polymerization Mo1d Im act Tensile Hard Heat sow I? t mg stmggth 83171711865; (1111055) dtiistor- 011111111? 0. emp., 5. sq. s ore on, p

Per- Per- Time Temp, 111 lbs.

Name cent Name cent hours no O. C. C.

1-.." Di-cinnamate of 1.4- 0.5 1.2-di-(4-chlor- 9.0 168 100 160 2.1 8600 80 64 104 dioxaned1ol2.3. phenyi-)ethane 2 Trimethallyl phosphate. 3.5 do /l2.5 168 100 160 1.0 6400 74 63 124. 3"... Dlaliylmaleate 5.0 do 47.5 168 80 160 0.9 6400 83 91 4"..- 2-chloraliyl crotonate 5.0 do 47. 5 168 80 160 0.8 6600 83 92 212 5 Z-chlorallyl furoate 5.0 do 47. 5 168 80 160 0.8 7100 84 89 225 Polymer was extracted with acetone and dried before molding.

' Example 3 The following Table 3 presents data illustrating the effect of the concentration of different plasticizing agents of the presenttype upon the physical properties of several styrene co-polymers. In each case, a mixture of monomeric styrene, the co-polymerizing agent, and the plasticizing agent was polymerized under the conditions indicated in the table, after which time the polymerized mass was ground, dried, molded to form the test specimen, and the properties 01' the latter were determined.

than the unplasticized co-polymer. It has a tensile strength of about 3900 lbs/sq. in. and a products. If desired, various dyes, pigments, I

Table 3 (Jo-polymerizing agent Plasticizing agent Polymerization Run g Impact Tensile Hard- -2%; Per Per Time Temp tempu 1: 1a ii fif iii $2 point 1 a a w g Q Name cent Name cent hours so. 0. l I O C.

1-.-- Di-cinnamate of lA-di- 0.5 168 100 160 0.9 0900 80 77 110 oxanedio1-2.3. 2..-. do 0.5 1.2-d1-(4-ch10b' 1.0 168 100 160 1.1 0000 86 84 117 4. 5 168 100 160 2. 7 6700 87 78 99 9.0 168 100 160 2.2 6400 84 67 98 13.0 168 100 160 0.8 5400 78 82 -.d0 16.5 168 100 160 0.8 4800 75 49 74 1.2-di-(2.5-di- 1.0 168 100 160 1.6 960) 76 v 88 127 chloigihenyb) Y 4. 5 168 100 ,160 1. 8 9500 76 78 116 9.0 168 100 160 1.9 96m 74 76 116 13.0 168 100 160 1.4 88]) 67 118 16.5 .168 1(1) 160 -1.1 6600 71 67 116 168 100 160 1.0 7300 84 83 105 1 .2-di-(4-ch b! 1. 0 168 100 160 1. 6 7400- 87 67 phenyb) ethane. I v d 4.5 168 100 160 0.9 0000 83 70 9.0 168 100 160 1. 0- 6400 74 63 124 12. 6 168 100 160 1. 1 7M 70 50 104 do 4.0 do 16.0 168 100 160 0.9 681) 64 44 06 Di-cinnamate of 1.4-di- 0.5 1.2-di-(2.4. -tri- 0.5 836 100 160 1.6 78 84 81 99 oxanediol-2.3. v chlorphe yl-) ethane. 0.5 .do 1.0 336 100 160 1.4 M 87 83 102 0.5 do 2.5 336 1.2 0900 84. &l 103 0.5 do. 5.0 336 100. 160 1.3 8711) 70 TI 98 0.5 do 9.0 336 100 160 0.8 8600 8) 66 90 Example 4 fillers, etc. may be incorporated with the new A mixture of 200 parts 01! momomeric styrene soluble in ethanol and acetone, but was capable of being swelled .to an insolublev gel in benzeneand similar aromatic hydrocarbon'solvents. Approximately 20 parts of this co-polymerwas added in finely divided form to about300 parts of a 3 per cent benzene solution of 1.2-di-(4-chlo'rphenyl-) ethane.

several hours, whereby theco-polymer swelled to a firm gel, after which the benzene was evaporated oif and the mixture dried under vacuum at 80 C. The co-polymer was obtained as a resin- The mixture was allowed to stand forproducts before molding to produce decorative eiI'ects or to modify the physical properties'of the molded product.

Other modes of applying the principle of our invention may be employed instead of. those explained, change being made as regards the process of the'ingredients employed, provided the process or the ingredients stated by arrv'of the following claims of 'the equivalent or such process or ingredients be employed, l 1

We therefore particularly point out and distinctly claim as our invention:

1. A composition of matter comprising "a copolymer of styrene and, as a plasticizing agent therefor, a di-(halophenyl-) alkane.

2. A composition of matter. comprising a co- 20 wherein R represents an alkylene radical, X represents a substituent selected from the group consisting of chlorine and bromine, and n represents an integer not greater than 5.

4. A composition of matter comprising a co- 25 polymer of styrene and, as a plasticizlng agent therefor, a di(chlorphenyl) alkane having the formula wherein R represents an alkylene radical and n represents an integer not greater than 3.

5. A composition of matter comprising an in- 35 soluble co-polymer of styrene and, as a plasticizing agent therefor, a di-(chlorphenyl-) alkane having the formula wherein R represents an alkylene radical and n represents an integer not greater than 3.

6. A composition of matter comprising an in- 45 soluble co-polymer of styrene and, as a plasticizing agent therefor, a di-(chlorpheny1-) alkane having the formula 5 C5 wherein R represents an alkylene radical containing not more than 5 carbon atoms.

7. A composition of matter comprising an in- 55 soluble co-polymer of styrene and the dicinnamate of 1.4-dioxanediol-2.3 and as a plasticizing agent therefor, a di-(chlorphenyl-) alkane having the formula (Cl) 1) WW? wherein R represents an alkylene radical containing not more than carbon atoms.

8. A composition of matter comprising an insoluble co-polymer of styrene and, as a plasticizing agent therefor, 1.2-di-(4-chlorphenyl-) ethane.

9. A composition of matter comprising an insoluble co-polymer of styrene and, as a plasticizing agent therefor, 1.2-di-(4-chlorpheny1-) propane.

10. A composition of matter comprising an insoluble co-polymer of styrene and, as a plasticizing agent therefor, 1.2-di-(4-chlorphenyl-) isobutane.

11. A composition of matter comprising the insoluble co-polymer of styrene and diallyl maleate plasticized with l.2-di-(4-chlorphenyl-) ethane.

12. A composition of matter comprising the insoluble co-polymer of styrene and the dicinnamate of 1.4-dioxanediol-23 plasticized with 1.2- di-( l -chlorphenyh) ethane.

13. A composition of matter comprising the insoluble co-polymer of styrene and trimcthallyl phosphate plasticizedwith 12.di-(4-ch1orphenyl-) ethane.

14. The process which comprises polymerizing styrene in the presence of aco-polymerizing agent and a di-(halophenyl-) alkane.

15. The process which comprises polymerizing styrene in the presence of a co-polymerizing agent and a di-(chlorphenyl-) alkane having the formula wherein R represents an alkylene radical containing not more than 5 carbon atoms.

EDGAR C. BRITTON. GERALD H. COLEMAN. 

